Grouping Chemicals for Safe Storage

1. Water-reactive, pyrophoric, self-reactive—such as lithium aluminum hydride, butyl lithium, potassium cyanide, and sodium azide. Does not include acidic water-reactive chemicals.

  • Store in secure, sealed secondary container in a dry location, e.g., a dry box or desiccator.
  • Isolate from other groups.
  • Separate from aqueous solutions and protect from water.
  • In refrigerator: Double-contain in bins or plastic bags.

2. Flammable chemicals—such as ethanol, methanol, hexane, toluene, and tetrahydrofuran. Includes combustible liquids with a flash point below 140ºF.

  • Store in flammable safety cabinet (a secondary container) or in a lab-safe refrigerator.
  • Groups 5 and 6 may be stored with this group within a flammable storage cabinet.

3. Liquid and solid oxidizers—such as 30 percent hydrogen peroxide, sodium dichromate, potassium permanganate, and sodium periodate.

  • Cannot be stored with Groups 1, 2, 4, 5, or 6.
  • Store by itself in a dedicated metal cabinet or desiccator.
  • May be stored within a secondary container in a lab cabinet or on a lab shelf segregated from Group 7.
  • Store double-contained in refrigerator segregated from other groups.
  • Large quantities of oxidizers (>3 kilograms) must be kept separate from all other chemicals in a dedicated cabinet.

4. Liquid and solid acids/corrosives—such as sulfuric acid, trifluoroacetic acid, glacial acidic acid, and nitric acid.

  • Store within secondary containment in a cabinet dedicated to acid storage (not with bases). Use secondary storage as spill control.
  • Use additional secondary containment for oxidizing acids and hydrofluoric acidsSeparate mineral acids from organic acids.
  • Not all acids are in Group 4 (e.g., benzoic acid is in Group 7).
  • Aqueous solutions of 2 mol/l (moles/liters) concentration and less are exempted and may be stored with Group 7 on lab shelves.

5. Liquid and solid bases/corrosives—such as ammonium hydroxide, sodium hydroxide (includes pellets), and potassium hydroxide.

  • Store within secondary containment in a cabinet dedicated to bases (never with acids). Use secondary containment as spill control.
  • May be stored in a flammable storage cabinet with Group 2 and/or Group 6. Keep separate using secondary containment.
  • Group does not include carbonates, triphosphates, or fluorides. Weak bases are not corrosive, e.g., potassium carbonate is Group 7.
  • Aqueous solutions of 2 M concentration and less are exempted and may be stored with Group 7.

6. Nonflammable solvents and other regulated chemicals—such as chloroform, methylene chloride, N-methylpyrollidinone, and dimethylformamide.

  • Group contains nonflammable liquids and Class III combustible organics having a flash point at or above 140ºF, and other regulated chemicals, including carcinogens, mutagens, and teratogens.
  • Store in sealed, secure, secondary containers.
  • Store in cabinets. If stored on shelves and in cabinets, secondary containment is required to contain spills.
  • May be stored within a flammable liquid storage cabinet with Group 2 and Group 5.

7. Low-hazard solids and liquids—such as calcium chloride, copper sulfate, MgSO4, potassium carbonate, boric acid, and PF compounds and intermediates.

  • Group also includes dilute aqueous acids and bases (less than or equal to 2 M) and other aqueous solutions.
  • Store in cabinets or on open shelves. Use secondary containment to control spills.
  • Segregate PF compounds and intermediates. Store in boxes or bins.
  • Store dry solids above liquids.

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